Prediction of obstetrical risk using maternal serum markers and clinical risk factors

Opinion de comité no 406 : Dépistage prénatal après FIV avec test génétique préimplantatoire des aneuploïdies

OBJECTIFS

Examiner l'approche du dépistage génétique prénatal et du diagnostic des anomalies chromosomiques dans les grossesses conçues par fécondation in vitro à la suite d'un test génétique préimplantatoire des aneuploïdies. PROFESSIONNELS CONCERNéS: Omnipraticiens, médecins de famille, obstétriciens, sages-femmes, infirmières, spécialistes en médecine fœto-maternelle, spécialistes en fertilité, conseillers en génétique, généticiens et autres professionnels de la santé qui participent au dépistage prénatal.

POPULATION CIBLE

Toute personne ou tout couple dont la grossesse est issue d'une fécondation in vitro et dont l'embryon a préalablement été soumis à un dépistage génétique préimplantatoire des aneuploïdies. DONNéES PROBANTES: Des recherches ont été effectuées dans les bases de données Medline, PubMed et Cochrane Library pour extraire la littérature publiée au plus tard en septembre 2018. DÉCLARATIONS SOMMAIRES.

Serum markers in quadruple screening associated with adverse pregnancy outcomes: A case-control study in China

BACKGROUND

We assessed whether the results of quadruple screening during pregnancy are associated with an increased risk of adverse pregnancy outcomes.

METHODS

We measured serum marker concentrations using quadruple screening in the second trimester of pregnancy and analyzed the relationship between adverse perinatal outcomes and serum markers in 12,124 pregnant women. A multivariate logistic regression analysis was used to evaluate the relative risk of quadruple screening and adverse pregnancy outcomes.

RESULTS

Compared with the control group, increased concentrations of alpha-fetoprotein (AFP) and inhibin A were risk factors for preeclampsia and preterm delivery; low concentrations of unconjugated estriol and high inhibin A were risk factors for pregnancy hypertension; an increased concentration of human chorionic gonadotropin (hCG) was a risk factor for gestational diabetes mellitus; high AFP, low hCG, and high inhibin A were risk factors for low birth weight; and low AFP and high hCG were risk factors for macrosomia.

CONCLUSIONS

Quadruple screening in the second trimester of pregnancy can provide early warning signs for maternal and fetal adverse pregnancy outcomes.

Committee Opinion No. 406: Prenatal Testing After IVF With Preimplantation Genetic Testing for Aneuploidy

OBJECTIVE

To review the approach to prenatal genetic screening and diagnosis for chromosomal abnormalities in pregnancies conceived through in vitro fertilization and following preimplantation genetic testing for aneuploidy.

INTENDED USERS

General practitioners, family physicians, obstetricians, midwives, nurses, maternal-fetal medicine specialists, fertility specialists, genetic counsellors, geneticists, and other health care providers involved in prenatal screening.

TARGET POPULATION

All individuals or couples who conceivd through in vitro fertilization and underwent preimplantation genetic testing for aneuploidy.

EVIDENCE

Literature published in or before September 2018 was retrieved through searches of Medline, PubMed, and the Cochrane Library. SUMMARY STATEMENTS.

Is maternal serum inhibin A a good predictor in preterm labor? - Experience from a community hospital in Taiwan

Background

We aimed to determine whether inhibin A could be a reliable and accurate predictor of preterm birth, and discuss the possible pathogenic processes of inhibin A leading to preterm birth.

Methods

A retrospective cohort study was conducted on consecutive singleton pregnant women who underwent the second-trimester quad screen test at a gestational age of 15–20 weeks at Keelung Chang-Gung Memorial Hospital from March 2011 to May 2015. Data including maternal characteristics and pregnancy outcomes were collected from an electric medical record database. Data regarding pregnancy terminations before a gestational age of 24 weeks and regarding pregnancies that involved chromosomal or congenital anomalies were excluded from this analysis. One-way analysis of variance was used to compare second-trimester α-fetoprotein, human chorionic gonadotropin, unconjugated estriol, and inhibin A in women with preterm deliveries versus those with term deliveries.

Results

Although a total of 935 women with singleton pregnancies were enrolled, pregnancy outcome and complete maternal data were obtained from only 770 (82.3%)of them. In total, 687 (89.2%) women delivered at or after 37 weeks of gestation and 83 (10.8%) women delivered before 37 weeks of gestation. The results showed that the inhibin A level was significantly increased in the preterm labor group (p = 0.009). A cutoff inhibin A value above 2.25 was identified statistical significantly in the preterm labor group.

Conclusions

From our results, an inhibin A level above 2.25 multiples of the median in the quad screen test may be associated with preterm labor afterward. Closely monitoring for uterine contractions or cervical length measurement in the second trimester may be indicated in patients with unexplained elevated inhibin A levels.

Does neighborhood socioeconomic status predict the risk of preterm birth? A community-based Canadian cohort study

OBJECTIVE

This study developed and internally validated a predictive model for preterm birth (PTB) to examine the ability of neighbourhood socioeconomic status (SES) to predict PTB.

DESIGN

Cohort study using individual-level data from two community-based prospective pregnancy cohort studies (All Our Families (AOF) and Alberta Pregnancy Outcomes and Nutrition (APrON)) and neighbourhood SES data from the 2011 Canadian census.

SETTING

Calgary, Alberta, Canada.

PARTICIPANTS

Pregnant women who were <24 weeks of gestation and >15 years old were enrolled in the cohort studies between 2008 and 2012. Overall, 5297 women participated in at least one of these cohorts: 3341 women participated in the AOF study, 2187 women participated in the APrON study and 231 women participated in both studies. Women who participated in both studies were only counted once.

PRIMARY AND SECONDARY OUTCOME MEASURES

PTB (delivery prior to 37 weeks of gestation).

RESULTS

The rates of PTB in the least and most deprived neighbourhoods were 7.54% and 10.64%, respectively. Neighbourhood variation in PTB was 0.20, with an intra-class correlation of 5.72%. Neighbourhood SES, combined with individual-level predictors, predicted PTB with an area under the receiver-operating characteristic curve (AUC) of 0.75. The sensitivity was 91.80% at a low-risk threshold, with a high false-positive rate (71.50%), and the sensitivity was 5.70% at a highest risk threshold, with a low false-positive rate (0.90%). An agreement between the predicted and observed PTB demonstrated modest model calibration. Individual-level predictors alone predicted PTB with an AUC of 0.60.

CONCLUSION

Although neighbourhood SES combined with individual-level predictors improved the overall prediction of PTB compared with individual-level predictors alone, the detection rate was insufficient for application in clinical or public health practice. A prediction model with better predictive ability is required to effectively find women at high risk of preterm delivery.

Elevated maternal serum-free β-human chorionic gonadotropin (β-hCG) and reduced risk of spontaneous preterm delivery. J Matern Fetal Neonatal Med 2018;32:3191-3196. [PMID: 29642747 DOI: 10.1080/14767058.2018.1459554]

Objective: To evaluate the relationship between first and second trimester maternal serum-free β-hCG and the risk of spontaneous preterm delivery (PTD). Study design: This was a case-control study of women evaluated and delivered at our institution from 2011 to 2015. Spontaneous PTD was defined as delivery before 37 weeks due to spontaneous preterm labor or premature rupture of membranes. Patient with multifetal gestation and those with medically indicated term or PTD were excluded. Results: Of 877 women meeting the inclusion criteria, 173 delivered preterm and 704 delivered at term, and 8.1% had high free β-hCG in one or both trimesters. High maternal first and/or second trimester free β-hCG (≥95th percentile) was associated with lower rates of PTD. Thirty-two women with high free β-hCG in both first and second trimesters delivered at term. Gestational age at delivery and birth weights were lower in women who did not have high free β-hCG in any trimester. Low free β-hCG (≤5th percentile) in either trimester was not associated with an increased or decreased likelihood of PTD. Logistic regression demonstrated an independent association of high free β-hCG (≥95th percentile) with a reduced likelihood of PTD. Stratified analysis revealed a stronger impact of this association in women with no prior history of PTD. Conclusions: High free β-hCG, in the absence of risk factors for medically indicated PTD, is associated with a reduced likelihood of spontaneous PTD and may represent a marker indicating lower risk.

Altered Biomarkers in Trophoblast Cells Obtained Noninvasively Prior to Clinical Manifestation of Perinatal Disease

A contributing factor to poor placental perfusion, leading to intrauterine growth restriction and preeclampsia, is the failure of invading extravillous trophoblast (EVT) cells to remodel the maternal uterine arteries during the first and second trimesters of pregnancy. Noninvasive assessment of EVT cells in ongoing pregnancies is possible beginning three weeks after conception, using trophoblast retrieval and isolation from the cervix (TRIC). Seven proteins were semi-quantified by immunofluorescence microscopy in EVT cells obtained between gestational weeks 6 and 20 from pregnancies with normal outcomes (N = 29) and those with intrauterine growth restriction or preeclampsia (N = 12). Significant differences were measured in expression of PAPPA, FLT1, ENG, AFP, PGF, and LGALS14, but not LGALS13 or the lineage marker KRT7. These findings provide for the first time direct evidence of pathology-associated protein dysregulation in EVT cells during early placentation. The TRIC platform provides a novel approach to acquire molecular signatures of EVT cells that can be correlated with pregnancy outcome.

Changes in antimüllerian hormone levels in early pregnancy are associated with preterm birth

OBJECTIVE

To determine the association of preterm birth with antimüllerian hormone (AMH) levels both in isolation and in combination with other markers of fetoplacental health commonly measured during integrated prenatal screening (IPS) for aneuploidy.

DESIGN

Retrospective case-control study.

SETTING

Not applicable.

PATIENT(S)

Pregnant women in Iowa who elected to undergo IPS and who subsequently delivered in Iowa, including women giving birth at <37 weeks' gestation and controls who delivered at ≥37 weeks' gestation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Probability of a preterm birth.

RESULT(S)

Second trimester AMH levels were not associated with preterm birth, either independently or after controlling for other markers of fetoplacental health. The AMH difference was not associated with preterm birth when modeled alone, but a statistically significant association was found after adjusting for maternal serum α-fetoprotein (MSAFP) and maternal weight change between the first and second trimesters. After stratifying the model by MSAFP level, most of the risk for preterm birth was identified in women with an MSAFP >1 multiple of the median and who had a stable or rising AMH level in early pregnancy.

CONCLUSION(S)

A lack of decline in the AMH level in early pregnancy can be used to identify women with a high probability for preterm birth, especially when MSAFP levels are >1 multiple of the median. Monitoring changes in the AMH level between the first and second trimesters of pregnancy may help identify women who would benefit from interventional therapies such as supplemental progesterone.

Combination of PAPPA, fhCGβ, AFP, PlGF, sTNFR1, and Maternal Characteristics in Prediction of Early-onset Preeclampsia

OBJECTIVE

To evaluate the efficacy of first-trimester markers-pregnancy-associated plasma protein A (PAPPA), free human chorionic gonadotropin β (fhCGβ), alpha-fetoprotein (AFP), placental growth factor (PlGF), and soluble tumor necrosis factor receptor-1 (sTNFR1) together with maternal characteristics (MC) for prediction of early-onset preeclampsia (EOPE).

METHODS

During 2005-2010, the abovementioned biomarkers were analyzed with logistic regression analysis in 64 EOPE and 752 control subjects to determine whether these biomarkers separately and in combination with MC would predict development of EOPE.

RESULTS

PAPPA, fhCGβ, and PlGF levels were lower, whereas AFP and sTNFR1 levels were higher in mothers with EOPE compared to controls. The combination of all markers with MC (age, weight, and smoking status) detected 48% of the mothers with EOPE, with a 10% false-positive rate (FPR).

CONCLUSIONS

First-trimester maternal serum levels of PAPPA, fhCGβ, AFP, PlGF, and sTNFR1, together with MC, are predictive of development of subsequent EOPE. These markers, along with MC, form a suitable panel for predicting EOPE.

Maternal estriol concentrations in early gestation predict infant telomere length

CONTEXT

Telomere biology plays a fundamental role in genomic integrity, cellular regeneration, physiology, aging, disease risk, and mortality. The initial setting of telomere length (TL) in early life has important implications for telomere maintenance and related disorders throughout the life span. However, little is known about the predictors of this initial setting.

OBJECTIVE

Given the established role of estrogen on adult TL and the role of estriol (E3) in the context of fetal development, the goal of this study was to test the hypothesis that higher maternal E3 concentration during early pregnancy is associated with longer infant telomere length.

DESIGN, PARTICIPANTS, AND SETTING

Study participants comprised a cohort of N = 100 infants followed prospectively from intrauterine life and birth through early childhood from a population-based, representative sample of pregnant mothers recruited in early pregnancy at university-based obstetric clinics in Southern California. Maternal unconjugated E3 concentrations were assessed in plasma in early gestation (around wk 15). Infant TL was assessed in buccal cells at approximately 15 months of age.

RESULTS

After accounting for the effects of potential confounding maternal and infant variables, there was a significant, independent effect of maternal E3 concentration on infant TL (unstandardized β = 0.297; P = .001; 95% Cl, 0.121-0.473). Specifically, a one-multiple-of-the-median (MoM) increase in maternal E3 concentration during early pregnancy was associated with a 14.42% increase in infant TL.

CONCLUSIONS

This study supports the concept of developmental plasticity of the telomere biology system and highlights specifically the role of a potentially modifiable intrauterine factor for additional mechanistic and clinical investigation.

Beyond Trisomy 21: Additional Chromosomal Anomalies Detected through Routine Aneuploidy Screening

Prenatal screening is often misconstrued by patients as screening for trisomy 21 alone; however, other chromosomal anomalies are often detected. This study aimed to systematically review the literature and use diagnostic meta-analysis to derive pooled detection and false positive rates for aneuploidies other than trisomy 21 with different prenatal screening tests. Non-invasive prenatal testing had the highest detection (DR) and lowest false positive (FPR) rates for trisomy 13 (DR: 90.3%; FPR: 0.2%), trisomy 18 (DR: 98.1%; FPR: 0.2%), and 45,X (DR: 92.2%; FPR: 0.1%); however, most estimates came from high-risk samples. The first trimester combined test also had high DRs for all conditions studied (trisomy 13 DR: 83.1%; FPR: 4.4%; trisomy 18 DR: 91.9%; FPR: 3.5%; 45,X DR: 70.1%; FPR: 5.4%; triploidy DR: 100%; FPR: 6.3%). Second trimester triple screening had the lowest DRs and highest FPRs for all conditions (trisomy 13 DR: 43.9%; FPR: 8.1%; trisomy 18 DR: 70.5%; FPR: 3.3%; 45,X DR: 77.2%; FPR: 9.3%). Prenatal screening tests differ in their ability to accurately detect chromosomal anomalies. Patients should be counseled about the ability of prenatal screening to detect anomalies other than trisomy 21 prior to undergoing screening.